<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.d0 {
				width: 80%;
				margin: 0 auto;
				border: 1px solid blue;
			}

			#d1 {
				width: 300px;
				height: 200px;
				background-color: red;
				float: left;
			}

			#d2 {
				width: 300px;
				height: 200px;
				background-color: orange;
				float: left;
			}

			#d3 {
				width: 300px;
				height: 200px;
				background-color: green;
			}

			.clearfix::after {
				content: "";
				display: block;
				height: 0;
				clear: both;
				visibility: hidden;
			}
		</style>
	</head>
	<body>
		<div class="d0 clearfix">
			<div id="d1">div1</div>
			<div id="d2">div2</div>
		</div>
		<div id="d3">div3</div>
	</body>
</html>
